Pushers



June 26, 1956 L. F. SMREKAR PUSHERS Filed July 24, 1953 IN VEN TOR.LARRY E SMREKAR United States Patent 6 PUSHERS Larry F. Smrekar, Solon,Ohio, assignor of one-half to John R. Cox and one-half to Alfred A.Abramoska Application July 24, 1953, Serial No. 370,094

6 Claims. 01. 279-46) My invention relates to pushers for feeding stockthrough a machine tool, such as an automatic screw machine and the like.

An object of my invention is the provision of improved means in a pusherof this general type for holding the pads held by the pusher againstcircumferential movement relative to the pusher.

Another object is the provision in a pusher for holding pusher padsagainst circumferential movement and at the same time to permit theready insertion and withdrawal of the pads from the pusher.

Another object is the provision for forming and locating stop means in apusher in a manner to protect the stop means against breakage ordistortion.

Another object is the provision of pad-engaging means in a pusherarranged to maintain the forward end of the pusher in advance of thestop means in a normal arcuate form.

A further object is the provision for maintaining the forward end of thepusher in circular form while providing a tongue extending radiallyinwardly of the pusher to engage a pad.

A further object is the provision of an improved combination of pusherand pads constructed and arranged to provide results heretofore notobtainable.

A still further object is the provision of a new construction in apusher having parts arranged to provide operating characteristics bothnovel and useful.

Other objects and a fuller understanding of the invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawing, in which:

Figure 1 is a side view of a pusher embodying my invention;

Figure 2 is a longitudinal sectional view taken through the line 22 ofFigure 1;

Figure 3 is an end view looking rearwardly at the forward end of mypusher in the direction of the arrows 3-3 of Figure 2; and

Figure 4 is an enlarged sectional view taken in the' direction of thearrows 44 of Figure 2.

My pusher has a hollow, generally cylindrical body 11 having a threadedrearward end 12 adapted to be threadably engaged to a reciprocating tubeor member through which stock or longitudinal work pieces are advancedand fed forwardly in a machine, such as an automatic screw machine, bythe pusher. The forward end 13 of the pusher is open and it is throughthis forward end 13 through which the' stock is advanced by'thep'usher'.

To provide resilient fingers 15, 16 and'17 from the wall of the pusher11, there'are three slots 14 extending longitudinally of the pusher fromthe forward end thereof. The slots 14 are relatively narrow at theforward end and of greater width at a location'intermediate the ends ofthe pusher, as seen in the drawing. The arrangement of the slots 14 issuch that the walls of the pusher intermediate the slots form fingersand the steel material thereof, being heat-treated, are of a resilientnature" to ice resiliently and firmly provide a grasping force upon thestock being advanced by the pusher.

Within the bore of the pusher and adjacent the forward end thereof arethree pads 18, 19 and 20. Each pad is of arcuate form and coincides ingeneral shape and dimension with the inner wall surface of each of thecorresponding fingers 15, 16 and 17. There is thus a hardened steel paddisposed on the inward wall surface of each of the fingers at theforward end of the pusher and arranged to engage the stock, such as arod, being advanced by the pusher. A shoulder located rearwardly of theforward end of the pusher limits the rearward movement of the pads inthe pusher as seen in Figure 2.

The forward end of the pusher has an inwardly disposed flange in theplane of the forward end 13 and around the circumferential extent of thepusher to hold the pads Within the pusher when the fingers are in acompressed condition.

The finger 15 has a tongue 21 formed therein on the wall of the pusher.This tongue 21 is formed by severing the metal around three sides of arectangular area and displacing the severed metal radially inward asseen in the drawing. The inward displacement is limited, however, sothat the amount of radial intrusion or extension of the tongue withinthe bore of the pusher is less than the wall thickness of the pusher.Thus, as seen in Figure 2, the forward end of the tongue 21, whiledisplaced inwardly, is also within the confines of the wall from whichit was cut and is thus embraced on all sides by the wall remaining inthe'cyiindrical plane of the pusher.

The pad 18 corresponding with the finger 15 has a slot or recess 22 cuttherein so as to accommodate the inwardly disposed tongue 21. The tongue21 thus is pushed within the slot or recess 22 of the pad 18. By thearrangement described and illustrated, the pad 13 is held againstcircumferential movement within the pusher by means of the interfittingof the tongue 21 in the member for limiting revolving or turning of thepads within the pusher. It is understood that separate pins havesometimes been mounted in a finger to extend radially inward and engagethe pad. However, the construction of the push'ers to accommodate suchpins and mounting of the pins is not economical and the pins, beingrelatively rigid, tend to fracture and wear. It is also understood thattongues have also been cut in the forward ends of pushers, but in thesecases the pusher was slit from the forward end thereof to leave thetongue free at the forward end of the pusher. Such tongues extendingfrom the extreme forward end of the pusher do not have the support andbracing. action that is sometimes necessary and they tend to break orbecome distorted.

Another disadvantage of having tongues extending from the extremeforward end of the pusher, instead of being spaced therefrom as aboveshown and described, is that in the heat-treating of the forward end ofthe pusher, a distortion is produced. Because of the interruption of thetongue in the forward end of the pusher in such other and previouspushers, the extreme forward end of the pusher, upon being heat-treated,tends to distort and become warped from a true circle. By the inventionherein disclosed, the forward end is not interrupted in a circumferential direction by a slit tongue and is retained in a true andundistorted circular form during heat treatment and thereafter.

Other advantages and benefits from the construction herein disclosedwillbe apparent to those acquainted with the construction and use of pushersof this general type.

To mount the pads 18, 19 and 20 within the pusher 11, the fingers 15, 16and 17 are slightly spread apart to open up somewhat the forward end ofthe pusher. While in this expanded position, the pads 18, 19 and 20 areinserted through the forward end of the pusher and placed against theinner wall of the pusher adjacent its forward end to the position shownin the drawing. Pad 18, having the slot or recess 22, is positionedunder the tongue 21 formed from the finger the pad 19 is positionedadjacent the finger 16 and the pad is positioned adjacent the finger 17.Upon release of the fingers, the resilient force thereof presses thepads toward each other and they are thereafter held in position by theresiliency of the fingers. The stock being fed by the pusher movesthrough the cylindrical open space between the pads and in eachoperation of the pusher, the pads grasp the stock to advance the same,as is well understood in the operation of pushers of this general type.

The present disclosure includes the description contained in theappended claims as well as that set forth above.

Although this invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and scope of the invention as hereinafterclaimed.

I claim as my invention:

1. In combination, a pusher for use in a machine tool, a plurality ofstock-receiving pads, said pusher being adapted to hold saidstock-engaging pads within its bore adjacent the forward end thereof,one of said pads having a recess formed at its forward end, said recesshaving a bottom wall extending forwardly and radially in a slope andhaving spaced side walls extending radially of the pad, said pusherbeing split at its forward end to provide a plurality of resilientfingers, each having an arcuate transverse shape at the forward end ofthe pusher, a pad-engaging stop member carried by one of said fingers tolimit circumferential movement of said pads in said bore relative to thepusher, said stop member being formed of a portion of said one fingerbeing partially cut from said one finger longitudinally thereof anddisplaced radially inward at a location spaced from said forward end ofthe pusher, said portion extending in a slope forwardly and radiallyinward of said pusher and having longitudinally extending and radiallydisposed side edges protruding in said bore to oppose in acircumferential direction said side walls of said recess to provideabutments to said pad moved in either circumferential direction, thesaid finger forwardly of said displaced portion being conformed to saidarcuate shape of the finger at said forward end, said stop member beingpositioned to interengage said one pad in said bore and to hold the sameagainst circumferential movement.

2. In combination, a pusher for use in a machine tool, a plurality ofstock-receiving pads, said pusher being adapted to hold saidstock-engaging pads within its bore adjacent the forward end thereof,one of said pads having a longitudinally extending recess at its forwardend and said recess having opposed and radially disposed sides, saidpusher being split at its forward end to provide a plurality ofresilient fingers each having an arcuate transverse shape at the forwardend of the pusher, a pad-engaging stop member earried by one of saidfingers to limit circumferential movement of said pads in said borerelative to the pusher, said stop member being a portion of the wall ofsaid one finger partially severed from said finger by a U-shaped cutwith the side arms of the U directed rearwardly of the U base to form atongue dependent on said finger at the rear of the severed portion, saidportion being pressed radially inward to protrude into said bore forengagement with said one pad, said portion extending forwardly of thepusher and being spaced from the forward end of the pusher, the saidfinger forwardly of said portion extending uninterruptedly in the saidarcuate transverse shape at said forward end, the sides of said severedportion extending in said bore in a longitudinal direction and beingradially disposed to provide abrupt stops opposing the sides of saidrecess to limit circumferential movement of said one pad in bothcircumferential directions.

3. In combination, a pusher for use in a machine tool, a plurality ofstock-engaging pads, said pusher being adapted to hold saidstock-engaging pads within its bore adjacent the forward end thereof,one of said pads having a forwardly extending recess at its forward end,said recess having opposed substantially parallel side walls, saidpusher being split at its forward end to provide a plurality ofresilient fingers each having an arcuate transverse shape at the forwardend of the pusher, a pad-eugaging stop member carried by one of saidfingers to limit circumferential movement of said one pad in said borerelative to said pusher, said stop member being a portion of the wall ofsaid one finger partially severed from said finger to form a forwardlydirected tongue dependent on said finger at the rearward end of thetongue, said portion being pressed radially inward to protrude into saidbore for interengagement with said one pad, the said portion havinglongitudinally extending and radially disposed side edges presentingabutments to the said side Walls of said recess to limit movement ofsaid one pad in both circumferential directions, the said portion beingspaced from the forward end of said pusher, the said finger forwardly ofsaid portion extending uninterruptedly in the said arcuate transverseshape at said forward end, the said portion protruding inwardly of saidbore a radial distance less than the thickness of said wall to provide abracing support for said portion along its said side edges.

4. In combination, a pusher for use in a machine tool, a plurality ofstock-engaging pads, said pusher being adapted to hold saidstock-engaging pads within its bore adjacent the forward end thereof,one of said pads having a recess at its forward end, said recess havingradially extending and substantially parallel side walls, said pusherbeing split at its forward end to provide a plurality of resilientfingers each having an arcuate transverse shape at the forward end ofthe pusher, a pad-engaging stop member carried by one of said fingers tolimit circurn ferential movement of said pads in said bore relative tothe pusher, said stop member being a portion of the wall of said onefinger partially severed from said finger to form a forwardly directedtongue dependent on said finger at the rearward end of the tongue, saidportion being displaced radially inward into said bore to extend withinthe recess of said pad to oppose the side walls of said recess, saidportion being located rearwardly of the forward end of the pusher toleave an uninterrupted wall of said arcuate transverse shape forwardlyof said portion at said forward end, the edge of said portion wheresevered from the wall of the pusher being substantially confined aroundits periphery by the said wall to brace the portion againstcircumferential displacement.

5. A pusher having a tongue extending into the bore thereof to hold padsin said bore adjacent the forward end of the pusher againstcircumferential movement, one of said pads having radially disposed andaxially extending walls opposed to each other to define a recesstherebetween at the forward end of said pad, said tongue beingpositioned in said bore to engage one of said pads, said tongue beingcut from the wall of the pusher along a line leaving the tonguedependent on said wall at the rearward end of said tongue and the tongueextended toward the forward end of the pusher, the forward end of thetongue being spaced rearwardly of the forward end of the pusher, saidtongue being displaced radially ward a distance less than the thicknessof the wall of the pusher from which cut to partially confine the tonguewithin the said wall, said tongue having substantially parallel sidewalls disposed radially of the pusher and forming abutments opposed tothe side walls of said recess to stop circumferential movement of saidpad relative to said pusher.

6. The combination of a pusher having a plurality of resilient fingersformed in the forward end portion thereof and a corresponding number ofstock-engaging pads carried in the pusher adjacent a respective finger,one of said fingers having a tongue cut therefrom at a locationrearwardly of the forward end of the pusher and displaced radiallyinward of the pusher to incline inwardly and forwardly of the pusher,said tongue being defined 6 by a U-shaped cut in which the base of the Uis circumferential of the pusher and spaced from the forward end thereofand in which the side-arms of the U extend in a rearward directionlongitudinally of the pusher, the side edges of the tongue formed by theside-arms of the U providing longitudinally disposed and oppositelyfaced abutments Within said pusher, one of said pads corresponding withsaid finger having a recess formed therein at its forward end foraccommodating said tongue, said recess having radially disposed andopposed side walls spaced to complementarily receive therebetween thesaid tongue, the tongue in said recess holding the said one pad againstcircumferential movement in the said pusher.

References Cited in the file of this patent UNITED STATES PATENTS2,187,170 OConnell Jan. 16, 1940 2,351,220 Martin June 13, 1944 MartinJan. 3, 1950

